Boring bars



Jan.. l0, 1967 l. KONWAL 3,2%397 BORING BARS 2 Sheets-Sheet l Filed Deo. 23, 1964 INVENTOR. .fg/www5 MAM/fm Jan. 10,1967 Komm/AL 39296,@@7

BORING BARS Filed Dec. 23, 1964 2 Sheets-Sheet 2 INVENTOR. //m was @Nw/144.

aww/5%@ )40.5 AVM/mfr United States Patent 3,296,897 BORING BARS Ignatius Konwal, 33S Parkview Ave., Elmhurst, Ill. 60126 Filed Dec. 23, 1964, Ser. No. 420,597 9 Claims. (Cl. 77-58) My invention relates to certain new and useful improvements in boring bars. Particularly the invention is characterized by an improved replaceable bit-supporting head which by a simple operation may be simultaneously adjusted and locked upon'y the boring bar.

Another important object is the provision of a simpliiied means for inserting and clamping a carbide or highspeed cutter bit in position upon the head.

Yet another object of the invention is a simple arrangement of a positive, removable connection between the head and the bar to eliminate chattering or other movement which would result in defective operation. In the present instance, the head is rmly drawn against the end of the boring bar by the operation of a simple tightening means.

Yet another feature of the invention is the novel arrangement for properly aligning the head with respect to the boring bar, thereby to position the cutter bit in a proper cutting path with respect to the work.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

FIG. 1 is a perspective view of the invention;

FIG. 2 is a fragmentary top plan View of the invention as viewed in FIG. l;

FIG. 3 is a fragmentary side elevational View of the invention as Viewed in FIG. 1;

FIG. 4 is a sectional detail view taken substantially on line 4 4 of FIG. 2;

FIG. 5 is a sectional detail View taken substantially on line 5 5 of FIG. 3;

FIG. 6 is a sectional detail view taken substantially on line 6 6 of FIG. 3;

FIG. 7 is a sectional detail view taken substantially on line 7 7 of FIG. 3;

FIG. 8 is a perspective View of the head embodied in my invention showing certain parts thereof in exploded relation with respect to each other;

FIG. 9 is a sectional detail view taken substantially on line 9 9 of FIG. 4, to enlarged scale.

The several `objects of my invention are preferably accomplished by the preferred form of construction shown in the accompanying drawings. In such drawings my improved boring bar includes an elongated shank 10 formed of such material as is best suited for the purpose.

Formed in the shank 10 are two aligned bores 11 and 12 of different diameters. Mounted in the larger bore 12 is a shaft 13 of a diameter less than the inside diameter of the bore 12. The shaft 13 is connected to the bar 1t) within the bore 12 by means of a transversely extending pin 14. The shaft 13 at its outer end portion terminates into a stud 15 which is of a diameter less than the shaft 13.

On opposite corresponding longitudinal sides of the stud 15 are provided flat surfaces 16. At the junction between the stud 15 and the shaft 13 is a shoulder 17. Embracing the stud 15 with its fingers 18 disposed to embrace the flat surfaces 16 of the stud 15, is a C washer 19. The purpose and function of such washer 19 is to restrain lateral movement of the stud 15 in the space 3,296,897 Patented dan. 10, 1967 ICC between the at surfaces 16 and adjacent walls of the bore 12.

Formed transversely through the shaft 13 is a threaded opening 2t) adapted to receive the threaded shanks 22 and 21 of screws 24 and 25. The top surfaces 26 ofthese screws may have impressed thereon a graduated scale 27.

A cutter bit head 29 is provided with a socket 30 which receives the stud 15. The head 29 is machined or otherwise milled to provide an arm 31 having a iiat side 32 provided with a recessed seat 33 which is adapted to receive a cutter bit 34. The arm 31 has a threaded opening 35 into which a threaded shank 36 of a clamping screw 37 is received.

A recessed portion 4t) (FIG. S) and an adjacent shoulder 41 are formed in the at side 32 of the arm 31. The recessed portion 4l) is slightly below the surface 34 of the bit 34 so that the screw 37 will engage the bit 34 and, when tightened, the screw 37 will bear directly on the bit and the shoulder 41 to firmly and securely hold the bit upon its seat 33.

Formed in one side of the head 29, is a threaded opening 42 into which is adapted to be threaded a stud screw 43. This screw 43 has a tapered end 44 which, when the screw 43 is threaded into the opening 42, will engage an adjacent wall of a tapered socket 45 formed in the stud shaft 15. The socket 45, as shown in FIG. 5, is of a larger diameter than the inner end of the screw 43 to provide the tapered wall 46 which, when eccentrically engaged by the screw 43, by cam action, will draw the head 29 tightly against the adjacent end 29 of the bar 10 to effect a firm and rigid connection between the head and the bar 10.

Formed in the head 29 at a substantially 90 angle with respect to the threaded opening 42 is a similar threaded opening 47 (FIGS. 4, 7). Threaded in this opening 47 is a stud screw 48. The stud screw 4S has a flat end portion which, when the screw 4&3 is threaded inwardly, will bear upon the adjacent at surface 16' of the stud shaft 15 (FIG. 7), thereby to secure the head 29 to the stud shaft 15 against axial rotation independent of the bar 10. Formed in the head 29 is a coolant hole 49 which communicates with a coolant `groove 49 formed in the stud shaft 15, as best seen in FIG. 7.

`One Iof the principal features which distinguish my invention from the prior art, is the employment of the stud screw 43 for bearing the head 29 firmly against the end of the boring bar 1G. Another feature is found in the employment of the axially :related screws 24 and 25 which may be adjusted relative to each other to shift the shaft 13 laterally of the lon-g axis of the boring bar, thereby to position the bit in a proper cutting relationship with respect to the work. This is accomplished in the following manner:

If it is required to adjust the head 29 in a direction to position the cutter bit in closer Irelationship to the work, as for example, in the direction indicated by the arrow in FIG. 4, lthe operator would loosen the screw 25 and tighten the screw 24. This latter action results in shifting the head slightly in the direction indicated by such arrow. IOn the other hand, if it is desired to adjust the head in a direction opposite to the arrow shown in FIG. 4, the operator loosens the screw 24 and tightens the screw 25. By this arrangement, the operator may obtain a microscopic adjustment of the head so as to properly position the bit in its required cutting engagement with the work. This feature, it will be noted, is accomplished without removing the head and without disturbing the position of the bit upon the head.

As a Agreat deal of strain is imposed upon the boring bar both radially and longitudinally during the cutting operation, the ability to adjust the head 4by means of the screws 24 and 25 and the ability to bear the head firmly against the end of the boring bar by means of the screw 43, results in a tool having the refilled qualities f pro ducing precision work of the maximum perfection. As the chattering of the bit is reduced to a minimum, if not entirely eliminated, the bit will have increased duration of usefulness. By merely removing the screws 43 and 48 (FIG. 7), the head 29 may be removed for replacement purposes. The cutter bit 34 may be of the multiple tip type.

While I have illustrated and described the preferred form of construction for carrying my invention into elfect, this is capable of variation and modication without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. A tool of the class described comprising a boring bar having a shank and a removable head at one end of the shank, said head having an arm projecting from the end thereof providing a relatively flat surface providing a seat for a bit, means for securing said bit in said seat, said shank and head having longitudinally aligned bores formed therein, a shaft having a .portion positioned in the bore of the shank and a stud shaft positioned in the bore of the head, said shaft being of a diameter less than the diameter of the bore of said shank, and means for connecting said shaft to said shank for lmovement relative to the bore of said shank in the plane of said bit seat to adjust the position of the bit relative to work being operated upon by said bit, and co-axially related means carried by said shank and engageable with said shaft at a point adjacent said connecting means for adjusting said bit relative to said work.

2. The device described in claim 1 in which said coaxially related means comprises a pin positioned through the shank and said shaft.

3. The device of claim 1 wherein said connecting means comprises a transversely threaded bore in said shaft and stud screws carried by said shank and threaded into said threaded bore from opposite sides of said shank to pivot the shaft in said -plane of said seat.

4. The device of claim 1 wherein said connecting means comprises a transversely threaded bore in said shaft and stud screws carried by said shank and threaded into said threaded bore from opposite sides of said shank to pivot the shaft in said plane 'of said seat, and wherein said coaxially related means comprises a pin positioned through the shank and said shaft.

5. The device of claim 1 characterized by the inclusion of camming means carried by said head and engageable with said shaft to draw the head tightly against said end of said shank.

6. The device of claim 2 characterized by the inclusion of camming means carried by said head and engageable with said shaft to draw the head tightly against said end of said shank.

7. The device of claim 3 characterized by the inclusion of camming means carried by said head and engageable with said shaft to draw the head tightly against said end of said shank.

8. The device of claim 4 characterized by the inclusion of camming means carried by said head and enga'geable with said shaft to draw the head tightly against said end of said shank.

9. The device of claim 5 in which said camming means comprises a stud screw carried by lthe head and having a tapered end portion eccentrically engageable in a tapered socket formed in said stud shaft, and means for removably connecting said head to said shaft in a position tightly against said end of said shank.

References Cited by the Examiner UNITED STATES PATENTS 3,050,828 8/1962 Cashman et al 29-96 WILLIAM W. DYER, JR., Primary Examiner.

G. A. DOST, Assistant Examiner. 

1. A TOOL OF THE CLASS DESCRIBED COMPRISING A BORING BAR HAVING A SHANK AND A REMOVABLE HEAD AT ONE END OF THE SHANK, SAID HEAD HAVING AN ARM PROJECTING FROM THE END THEREOF PROVIDING A RELATIVELY FLAT SURFACE PROVIDING A SEAT FOR A BIT, MEANS FOR SECURING SAID BIT IN SAID SEAT, SAID SHANK AND HEAD HAVING LONGITUDINALLY ALIGNED BORES FORMED THEREIN, A SHAFT HAVING A PORTION POSITIONED IN THE BORE OF THE SHANK AND A STUD SHAFT POSITIONED IN THE BORE OF THE HEAD, SAID SHAFT BEING OF A DIAMETER LESS THAN THE DIAMETER OF THE BORE OF SAID SHANK, AND MEANS FOR CONNECTING SAID SHAFT TO SAID SHANK FOR MOVEMENT RELATIVE TO THE BORE OF SAID SHANK IN THE PLANE OF SAID BIT SEAT TO ADJUST THE POSITION OF THE BIT RELATIVE TO WORK BEING OPERATED UPON BY SAID BIT, AND CO-AXIALLY RELATED MEANS CARRIED BY SAID SHANK AND ENGAGEABLE WITH SAID SHAFT AT A POINT ADJACENT SAID CONNECTING MEANS FOR ADJUSTING SAID BIT RELATIVE TO SAID WORK. 